Abstract

An apparatus 1 to measure and/or check the spatial position and angular orientation of characteristic spots or areas 3 in mechanical structures or members, particularly in motor-vehicle structural components such as bodies or wheels. The apparatus substantially comprises an articulated arm 4 provided with a number of pivot points 5 and carrying, at a free end thereof, a tracer point 10 adapted to be positioned close to the characteristic spots or areas 3 of the structure to be measured or checked. Located at the pivot points 5 of the articulated arm 4 are displacement transducers 16 which send electrical signals to a computer depending upon a variation in the configuration taken by the pivot points 5 as compared with corresponding reference configurations. The computer instantaneously give the spatial coordinates of each characteristic spot or area 3 of structure 2 that are individually contacted by the tracer point 10 and, when necessary, compares them with corresponding reference coordinates to ascertain possible differences due to construciton faults or damages in structure 2.